The present invention relates to self-aligning hydrostatic shoe bearings.
Bearings of the above type are commonly used in large mills for grinding ore or the like. These mills generally comprise a large cylindrical body of considerable weight having runners at opposite ends which are journalled in hydrostatic shoe bearings. These hydrostatic bearings are well known and as shown in British Patent Nos. 1,330,484, 1,309,518 and 1,359,839, generally consist of a shoe having an arcuate supporting surface for the runner, a cavity defining a pocket in the supporting surface for a fluid medium, for example, oil. During operation of these bearings, oil is continuously delivered to the pocket and flows out on the upper surface of the shoe whereby the runners are supported on an oil film under high pressure. When the mill is stopped, the supply of oil to the shoe is cut off with the result that the runner weight bears directly against the bearing shoe. The radius of the runner is generally smaller than the radius of curvature of the bearing shoe so that a line contact occurs between the runner and bearing shoe when the machine is at rest. The bearing shoe is usually supported on a fixed support by means of a ball disposed generally centrally of the cavity or pocket for the pressure fluid. Thus, there is no support of the runner of the mill at the central part of the pressure fluid pocket directly over the ball support. Consequently, the load on the shoe will tend to bend the sides of the shoe. In view of the considerable weight of these mills, the surface pressure at the line contact is very high thus presenting the risk of surface damage, such as smearing.